Answer:
Explanation:
"The sum of -3x^2 or 3x^2 and 7x^2 is 10x^2" is false as it now stands.
If we combine -3x^2 and 3x^2, we get 0, so:
"The sum of -3x^2 or 3x^2 and 7x^2 is 10x^2" is equivalent to
"The sum of (expression) and 7x^2 is 10x^2".
Subtracting 7x^2 from both sides yields (expression) = 3x^2.
So: Although "The sum of -3x^2 or 3x^2 and 7x^2 is 10x^2" is false,
"The sum of 3x^2 and 7x^2 is 10x^2" is true, and the formerly missing term is 3x^2.